Evaluating Cooking Losses Of Meat Emulsions By Light Scatter

Frankfurters are the most popular comminuted products in the US and account for the 25% of all sausages sold (NHDSC, 2006). Base on an average cooking loss (weight, %) of 2.64 (optimum chopping conditions), the estimated economic loss resulting from non optimum emulsion stability during the cooking process was estimated to range between 0.2 and 1.65 billion dollar per year (only in the US). A number of off-line variables have been defined to characterize meat emulsions (emulsion capacity, emulsion stability, droplet size, etc.). However, no method is currently available to predict the emulsion stability during the chopping process, while corrective actions are still feasible. Improving process control and automation of the meat emulsification process will reduce the economical impact of emulsion breakdown in meat industry worldwide. The objective of this study was to determine if light backscatter intensity measured during the chopping process could be used to predict the susceptibility of the emulsion to loose weight during cooking. A completely randomized factorial design with two fat levels (15, 30%), two hydrolyzed potato protein (HPP) levels (0, 2.5%) and three replicates were used in this study to obtain a wide range of lipid oxidation susceptibility. HPP levels were included as a natural source of antioxidant agents. Adjusted proportions of pork lean and fat meats, HPP, NaCl, water and ice were chopped up to an emulsion temperature of 15°C. The optical properties of the raw emulsions were characterized by visible-NIR light backscatter measurements. CIELAB colour coordinates of raw emulsions were determined using a portable colorimeter. Weight loss of cooked emulsions was also measured. The best single-, two-, threeand four-variable models for predicting cooking losses were selected using the SAS Maximum R procedure. The variables taken into consideration in the selection procedure were the colour coordinates and the optical parameters obtained from the light scatter spectral scan. Several colour and light scatter parameters showed potential for online prediction of cooking loss.